Page 117025 Instruction Manual (Rev. 2)The eccentric (3) and the valve link pin (4) are provided with sealed bearings which arepermanently lubricated and protected from dust: they may require attention after severalthousand hours of operation, at which time a major overhaul of the entire mechanism isrecommended.5.2.3 Lubricating Cylinder/PistonEvery 200 hours of operation it is wise to lubricate the cylinder and valve gear (see fol-lowing paragraph). It is possible to inject some grease into the cylinder open end with asyringe, when the piston is stopped at its most forward position (see also paragraph 6.1-Stroke Volume for guidance).However, the O-ring spacing combined with the limited piston travel would lead to an un-even and limited spreading of grease over the working surface. In particular, the inner O-ring would hardly get any grease.Not to speak of the problem of removing residual grease and cleaning. For a flawless job,it is recommended that you take the piston out, see paragraph 5.2.1-Changing Cylin-der/Piston Assembly.Remove the residual grease with a cloth; apply fresh grease to fill up ring grooves. Re-move any excess. Insert the piston and reassemble the whole.5.2.4 Lubricating Valve GearThe valve gear is lubricated via the grease cup (22) placed on the valve block top, seeFigure 6 “Cylinder/Piston Assembly”. A lithium-grease tube is supplied with the standardpackage, see 8-ORDERING INFORMATION.When turning the cap clockwise, the grease contained in the cup is squeezed via twoboreholes into the valve seat, where it is distributed by the tapered sections of the spindle(13). An even film of grease assures adequate air seal, quiet operation, minimum frictionand wear.1/4 turn of the cap every 8 hours of operation is sufficient to deliver adequate lubricant.Occasional inspection of the cup (and consequent refilling if empty!) will prevent the riskof running dry, which might damage the working surfaces of the spindle and valve seat.An excess of grease squeezed into the valve will not cause any damage. The pumpingaction will squirt the excess into the cylinder or out via the “to animal” port.If you need to clean excess grease from the air ports, use a cotton swab, not a metallictool such as a screwdriver; an untoward movement may cause a scratch in the polishedvalve seat or spindle which will compromise the air seal.5.2.5 Variable Stroke DiskThe variable stroke disk (7) turns on generously dimensioned, permanently lubricatedthrust ball bearings. The pinion/ring gear which rotates the disk is also permanently lubri-cated (14 & 16).